The specific aims of this proposal are: 1) To determine if liposomes containing Interleukin 1 on their outer membranes may be used as synthetic macrophages to present antigen to lymphocytes, initiate the lymphokine cascade, kill IL 1-sensitive tumor cells, and stimulate the growth of IL 1- responsive cells. 2) To evaluate the biological activity of IL 1-liposomes in vivo for the ability to initiate the sequelae of inflammation, to induce angiogenesis, and to inhibit the growth and metastasis of tumors. 3) To elucidate the molecular mechanisms of macrophage activation which lead to induction and translation of IL 1-specific mRNA and to evaluate the effects of specific inhibitors of macrophage activation. 4) To determine the series of post-translational intracellular events which lead to the secretion of IL 1 from the monocyte and the deposition and anchoring of IL 1 in the membrane. 5) To further evaluate synthetic peptides which have been demonstrated to inhibit the biological activity of human IL 1.